1. Field of the Invention
The present invention relates to a surgical instrument used for operating a needle, etc. when cardiovascular tracts, urinary tracts, and tissues in body cavities are sutured.
2. Description of the Related Art
In recent surgery, a suturing operation has been performed to suture tissues while operating, e.g., a curved needle with a thread. In a surgical instrument for use in the suturing operation, a treatment portion is provided, for example, at the distal end of an insert section. When an anastomosis opening is sutured, a surgeon finely operates the needle by using the treatment portion of the surgical instrument to progress the suturing stitch by stitch with close attention. For that reason, the suturing operation in surgery has been a factor that prolongs the surgery time.
Particularly, in surgery to be performed within a limited space, e.g., in surgery using an endoscope, the insert section is generally inserted into a body cavity through a trocar or the like. Therefore, a lot of training is required until a surgeon has become able to operate the needle by using the treatment portion provided at the distal end of the insert section in a fine manner as intended.
For example, U.S. Pat. No. 5,810,877 discloses a surgical instrument for holding a needle, e.g., a suturing needle, used in anastomosing or suturing cardiovascular tracts and urinary tracts. The disclosed surgical instrument has a treatment portion of the so-called pincers structure and holds a needle by pinching it.
Also, U.S. Pat. No. 5,951,575 discloses a needle carrier aiming at improved convenience in use. When suturing blood vessels, organs, etc., the disclosed needle carrier enables a curved needle to be inserted by actively moving the needle following the curvature of the needle while the curved needle is grasped.
Further, U.S. Pat. No. 6,322,578 discloses a grasping forceps used in a body cavity for various applications, such as spreading tissues and handling threads.
The surgical instrument, the needle carrier, and the grasping forceps are each inserted into the body cavity through a trocar or the like. When the suturing operation is performed by using the needle carrier and the grasping forceps, the surgeon generally operates the needle carrier by one hand and operates the grasping forceps by the other hand.
In the suturing operation, the surgeon holds the proximal end of a needle by the needle carrier and places a needle tip at a predetermined position in an organ. Then, the surgeon actively moves the needle such that the needle is inserted in place. The tip of the needle inserted from the predetermined position in the organ passes through the organ and is projected out of the organ surface again. The surgeon holds the needle tip projected out of the organ by the needle carrier or the grasping forceps and then draws the needle out of the organ by making an operation at hand. One stitch of suturing is thus completed.
When drawing out the needle by the needle carrier, the surgeon temporarily releases the proximal end of the needle from the held state. Thereafter, the surgeon moves the needle carrier from the proximal end to the tip of the needle and draws out the needle by holding the needle tip with the needle carrier.
On the other hand, when drawing out the needle by using the grasping forceps, the surgeon first inserts the needle while operating the needle carrier by one hand. Then, the surgeon grasps the needle tip and draws out the needle while operating the grasping forceps by the other hand. By thus inserting the needle with the needle carrier and drawing out the needle with the grasping forceps, the needle can be more smoothly drawn out and the suturing operation can be finished in a shorter time than the case of inserting and drawing out the needle with only the needle carrier.
When the needle inserted in, e.g., a luminal tissue is drawn out, the needle requires to be moved following the curved shape of the needle so as to avoid the tissue from being damaged. In the surgery using an endoscope, however, a region in which the treatment portion is allowed to move is limited. Let us now look at a manual operation of drawing out a suturing needle 33 in the form of a curved needle inserted in a first luminal organ 31 and a second luminal organ 32 as shown in FIG. 1, for example, by using a grasping forceps 34.
First, the surgeon introduces the grasping forceps 34 into a body cavity through a trocar 36 stuck in a patient body wall 35. In this state, the grasping forceps 34 is restricted in its movable region other than the direction in which it is advanced and retracted with respect to the trocar 36. Numeral 37 denotes a portion which has been sutured, 38 denotes a suturing thread, and 39 denotes an opening to be sutured.
Then, as shown in FIG. 2, the surgeon grasps a needle tip 33a by the grasping forceps 34 introduced through the trocar 36. From that state, the surgeon may try to draw out the suturing needle 33, for example, by moving the grasping forceps 34 to pull it outward of the patient body wall 35 as indicated by an arrow A. However, when the needle is drawn out in such a manner, a tensile force is applied from the suturing needle 33 to the luminal organ 32 as indicated by an arrow B in FIG. 3, thus resulting in a risk that the suturing needle 33 cannot be easily drawn out.